Denmark, providing one of two container vessels taking delivery of Syrian chemical weapons for destruction, urged Damascus on Tuesday to expedite the process and said it could not wait beyond a June 30 deadline, Reuters reported.

Syria missed several interim deadlines for relinquishing its toxic stockpile, although most of the declared amount has now been removed or destroyed, and Western officials are concerned about discrepancies and ambiguities in Syria's inventory declaration that could leave some of its arsenal intact.

Damascus's poison gas program was to be completely destroyed by June 30 but deadline is unlikely to be met, diplomats say, partly because it will take at least two months for a U.S. ship to destroy the chemical agents at sea.

Two cargo ships - from Denmark and Norway - from a Nordic maritime force remain in the eastern Mediterranean taking incremental deliveries of Syrian toxins.

"It is the ambition of Denmark, of the world community that we will be able to meet the deadline," Foreign Minister Martin Lidegaard told Reuters Television aboard the Ark Futura, a vessel whose latest cargo consisted of 110 containers of mustard gas and precursor chemicals for sarin and VX nerve gas.

"We have mandated our ships to stay here until the 30th of June, but we haven't mandated them any longer and that is why we urge the Syrian government to move now; we can't stay here forever, and we cannot keep on waiting forever," he said.

Syria has been removing 1,300 tons of chemical weapons under a deal reached last year which averted Western air strikes over a sarin gas attack on rebel-held suburbs of the Syrian capital Damascus in August.

Just over 92 percent of chemicals have been handed over to a joint task force of the United Nations and the Organization for the Prohibition of Chemical Weapons.